1. Field of the Invention
This present invention relates to hydraulic couplings used in undersea drilling and production applications and junction plates used to support the opposing members of the coupling. More particularly, the invention involves a junction plate assembly configured to bring the male and female coupling members into engagement or disengagement at remote subsea locations.
2. Description of Related Art
Subsea hydraulic couplings are old in the art. The couplings generally consist of a male member and a female member with sealed fluid passageways connecting therebetween. The female member generally is a cylindrical body with a relatively large diameter longitudinal bore at one end and a relatively small diameter longitudinal bore at the other. The small bore facilitates connections to hydraulic lines, while the large bore seals and slidingly engages the male member of the coupling. Subsea hydraulic couplings are shown, for example, in U.S. Patents issued to Robert E. Smith III assigned to National Coupling Company Inc. of Stafford, Tex.
The male member includes a cylindrical body with a probe section approximately equal to the diameter of the female member bore, and a connection at its other end to facilitate connection to hydraulic lines. When the probe section of the male member is inserted into the bore of the female member, according to various embodiments of the device, fluid flow is established between the male and female members.
A male member and female member are generally connected to opposing junction plates of a manifold and are held together by bolts or hydraulic members attached to the plates. The male member is commonly attached to one junction or manifold plate, while the female member is attached to an opposing plate so as to face the male member and align with it. The male and female members may be attached to the junction plates or manifold plates using various means, such as set screws or threads. Techniques for attaching the members to such plates are well known to those skilled in the art.
Typically, several subsea hydraulic connectors are grouped together on each junction or manifold plate. For example, two or more coupling members may be attached to each opposing plate. In the subsea environment, a diver or remote operating vehicle is used to connect the opposing plates together, and thereby connect the opposing coupling members on each of the plates. The coupling members are typically simultaneously connected and the opposing plates are locked together.
High separational forces are transferred to the opposing junction plates, due to the separational forces of the high pressure hydraulic fluid in each coupling member. In many cases, the plates must be relatively thick and heavy in order to withstand high separational forces. The plates are typically stainless steel and between one and one and one-half inches in thickness.
U.S. Pat. No. 4,915,419 to Robert E. Smith III relates to a sliding lock plate for locking together simultaneously male and female coupling members on opposing junction plates. Various other locking devices have been used or proposed to lock together the male and female coupling members attached to junction plates.
These locking devices lock the coupling members together after the male end coupling members are fully engaged, and do not assist in bringing the male and female members together into full engagement before locking. In many cases, substantial axial forces are needed to bring all the male coupling members on a junction plate into full engagement with the female coupling members on the opposing junction plate. Hydraulic systems at subsea depths are subject to a number of different forces tending to inhibit the connection of male and female coupling members. For example, subsea pressures at significant ocean depths, high hydraulic pressure in the system, and mechanical forces required to open valves and connect junction plates are among the factors of concern. A combination of these forces may result in difficulty simultaneously engaging the male and female coupling members on opposing junction plates, and also result in substantial separational forces after the coupling members are connected.
Attempts have been made to simultaneously bring the junction plates together, including threaded devices. However, threaded connections have the disadvantages of marine growth buildup in the threads and galling of the threads. Another alternative is lock sleeves for bringing together subsea hydraulic connectors. However, lock sleeves are relatively heavy and bulky, which is undesirable in the subsea environment. Other problems are caused by a buildup of silt, ocean debris and marine growth in the lock sleeves. Typically, the lock sleeve systems includes lock sleeves connected to a plate interposed between the male and female junction plates. As the intermediate plate is pulled back, all of the lock sleeves on the coupling members are simultaneously pulled back and then released. The buildup of silt, ocean debris and marine growth may result in jamming the lock sleeves and especially the locking balls.
Accordingly, a simple and highly reliable mechanism is needed for solving the problem of simultaneously bringing male and female coupling members on junction plates into engagement in a subsea environment.
The present invention overcomes the above mentioned problems and disadvantages by providing a junction plate or manifold plate assembly for hydraulic coupling members, wherein the junction plates are moved together by a cam and cam follower attached to a central shaft. One of the junction plates to which coupling members are connected includes one or more sloping cam surfaces. The central shaft extending between the junction plates has one or more cam followers, which may be rollers or bearings. When the central shaft is rotated, each cam follower moves up the sloped cam surface. The sloped cam surface translates the rotational movement of the central shaft to axial movement to bring the two manifold plates closer together. When the cam follower reaches the end of the sloped cam surface, the male and female coupling members are fully engaged. The rotational movement necessary to bring the junction plates and couplings together may be accomplished by a diver or with a remote operating vehicle at subsea depths.